Diabetes can have an adverse impact on your eyes. Too much glucose (sugar) in the blood over long periods of time can result in what is commonly referred to as diabetic retinopathy.
The retina is the lining at the back of the eye. Your retinas have tiny blood vessels that are easily broken by high blood glucose. When these vessels break, blood leaks into the eye, preventing light from reaching the retina, causing floating spots (see image) or nearly total darkness.
With diabetes, impaired sight may not be noticed immediately. The impact is generally noticed slowly over time and can occur first in one eye and then the other.
Even diabetics with well-managed blood glucose can have slight eye damage over time due to small variations in blood sugar levels. That is why it is always a good idea to have your eyes checked annually by an ophthalmologist.